Search for promptly produced heavy quarkonium states in hadronic Z decays

Zeitschrift für Physik C Particles and Fields Springer Nature 69:1 (1995) 575-583

Authors:

P Abreu, W Adam, T Adye, E Agasi, I Ajinenko, R Aleksan, GD Alekseev, PP Allport, S Almehed, SJ Alvsvaag, U Amaldi, S Amato, A Andreazza, ML Andrieux, P Antilogus, W-D Apel, Y Arnoud, B Åsman, J-E Augustin, A Augustinus, P Baillon, P Bambade, F Barao, R Barate, G Barbiellini, DY Bardin, GJ Barker, A Baroncelli, O Barring, JA Barrio, W Bartl, MJ Bates, M Battaglia, M Baubillier, J Baudot, K-H Becks, M Begalli, P Beilliere, Yu Belokopytov, K Belous, AC Benvenuti, M Berggren, D Bertrand, F Bianchi, M Bigi, MS Bilenky, P Billoir, D Bloch, M Blume, S Blyth, V Bocci, T Bolognese, M Bonesini, W Bonivento, PSL Booth, G Borisov, C Bosio, S Bosworth, O Botner, B Bouquet, C Bourdarios, TJV Bowcock, M Bozzo, P Branchini, KD Brand, T Brenke, RA Brenner, C Bricman, L Brillault, RCA Brown, P Bruckman, J-M Brunet, L Bugge, T Buran, T Burgsmueller, P Buschmann, A Buys, M Caccia, M Calvi, AJ Camacho Rozas, T Camporesi, V Canale, M Canepa, K Cankocak, F Cao, F Carena, P Carrilho, L Carroll, C Caso, MV Castillo Gimenez, A Cattai, FR Cavallo, L Cerrito, V Chabaud, Ph Charpentier, L Chaussard, J Chauveau, P Checchia, GA Chelkov, R Chierici, P Chliapnikov, P Chochula, V Chorowicz, V Cindro, P Collins, JL Contreras, R Contri, E Cortina, G Cosme, F Cossutti, HB Crawley, D Crennell, G Crosetti, J Cuevas Maestro, S Czellar, E Dahl-Jensen, J Dahm, B Dalmagne, M Dam, G Damgaard, PD Dauncey, M Davenport, W Da Silva, C Defoix, A Deghorain, G Della Ricca, P Delpierre, N Demaria, A De Angelis, H De Boeck, W De Boer, S De Brabandere, C De Clercq, C De La Vaissiere, B De Lotto, A De Min, L De Paula, C De Saint-Jean, H Dijkstra, L Di Ciaccio, F Djama, J Dolbeau, M Donszelmann, K Doroba, M Dracos, J Drees, K-A Drees, M Dris, Y Dufour, F Dupont, D Edsall, R Ehret, G Eigen, T Ekelof, G Ekspong, M Elsing, J-P Engel, N Ershaidat, B Erzen, M Espirito Santo, E Falk, D Fassouliotis, M Feindt, A Ferrer, TA Filippas, A Firestone, P-A Fischer, H Foeth, E Fokitis, F Fontanelli, F Formenti, B Franek, P Frenkiel, DC Fries, AG Frodesen, R Fruhwirth, F Fulda-Quenzer, J Fuster, A Galloni, D Gamba, M Gandelman, C Garcia, J Garcia, C Gaspar, U Gasparini, Ph Gavillet, EN Gazis, D Gele, J-P Gerber, M Gibbs, R Gokieli, B Golob, G Gopal, L Gorn, M Gorski, Yu Gouz, V Gracco, E Graziani, G Grosdidier, K Grzelak, S Gumenyuk, P Gunnarsson, M Gunther, J Guy, F Hahn, S Hahn, Z Hajduk, A Hallgren, K Hamacher, W Hao, FJ Harris, V Hedberg, R Henriques, JJ Hernandez, P Herquet, H Herr, TL Hessing, E Higon, HJ Hilke, TS Hill, S-O Holmgren, PJ Holt, D Holthuizen, S Hoorelbeke, M Houlden, J Hrubec, K Huet, K Hultqvist, JN Jackson, R Jacobsson, P Jalocha, R Janik, G Jarlskog, P Jarry, B Jean-Marie, EK Johansson, L Jonsson, P Jonsson, C Joram, P Juillot, M Kaiser, F Kapusta, K Karafasoulis, M Karlsson, E Karvelas, S Katsanevas, EC Katsoufis, R Keranen, BA Khomenko, NN Khovanski, B King, NJ Kjaer, H Klein, A Klovning, P Kluit, B Koene, P Kokkinias, M Koratzinos, V Kostioukhine, C Kourkoumelis, O Kouznetsov, P-H Kramer, M Krammer, C Kreuter, J Krolikowski, I Kronkvist, Z Krumstein, W Krupinski, P Kubinec, W Kucewicz, K Kurvinen, C Lacasta, I Laktineh, S Lamblot, JW Lamsa, L Lanceri, DW Lane, P Langefeld, V Lapin, I Last, J-P Laugier, R Lauhakangas, G Leder, F Ledroit, V Lefebure, CK Legan, R Leitner, Y Lemoigne, J Lemonne, G Lenzen, V Lepeltier, T Lesiak, D Liko, R Lindner, A Lipniacka, I Lippi, B Loerstad, M Lokajicek, JG Loken, JM Lopez, A Lopez-Fernandez, MA Lopez Aguera, D Loukas, P Lutz, L Lyons, J MacNaughton, G Maehlum, A Maio, V Malychev, C Maocun, J Marco, B Marechal, M Margoni, J-C Marin, C Mariotti, A Markou, T Maron, C Martinez-Rivero, F Martinez-Vidal, S Marti i Garcia, F Matorras, C Matteuzzi, G Matthiae, M Mazzucato, M Mc Cubbin, R Mc Kay, R Mc Nulty, J Medbo, C Meroni, S Meyer, WT Meyer, A Miagkov, M Michelotto, E Migliore, L Mirabito, WA Mitaroff, U Mjoernmark, T Moa, R Moeller, K Moenig, MR Monge, P Morettini, H Mueller, LM Mundim, WJ Murray, B Muryn, G Myatt, F Naraghi, FL Navarria, S Navas, P Negri, S Nemecek, W Neumann, N Neumeister, R Nicolaidou, BS Nielsen, M Nieuwenhuizen, V Nikolaenko, P Niss, A Nomerotski, A Normand, W Oberschulte-Beckmann, V Obraztsov, AG Olshevski, A Onofre, R Orava, K Osterberg, A Ouraou, P Paganini, M Paganoni, P Pages, H Palka, Th D Papadopoulou, K Papageorgiou, L Pape, C Parkes, F Parodi, A Passeri, M Pegoraro, L Peralta, H Pernegger, M Pernicka, A Perrotta, C Petridou, A Petrolini, M Petrovyck, HT Phillips, G Piana, F Pierre, M Pimenta, M Pindo, S Plaszczynski, O Podobrin, ME Pol, G Polok, P Poropat, V Pozdniakov, M Prest, P Privitera, N Pukhaeva, D Radojicic, S Ragazzi, H Rahmani, J Rames, PN Ratoff, AL Read, M Reale, P Rebecchi, NG Redaelli, M Regler, D Reid, PB Renton, LK Resvanis, F Richard, J Richardson, J Ridky, G Rinaudo, I Ripp, A Romero, I Roncagliolo, P Ronchese, L Roos, EI Rosenberg, E Rosso, P Roudeau, T Rovelli, W Ruckstuhl, V Ruhlmann-Kleider, A Ruiz, H Saarikko, Y Sacquin, A Sadovsky, G Sajot, J Salt, J Sanchez, M Sannino, M Schimmelpfennig, H Schneider, U Schwickerath, MAE Schyns, G Sciolla, F Scuri, P Seager, Y Sedykh, AM Segar, A Seitz, R Sekulin, RC Shellard, I Siccama, P Siegrist, S Simonetti, F Simonetto, AN Sisakian, B Sitar, TB Skaali, G Smadja, N Smirnov, O Smirnova, GR Smith, R Sosnowski, D Souza-Santos, T Spassov, E Spiriti, P Sponholz, S Squarcia, C Stanescu, S Stapnes, I Stavitski, F Stichelbaut, A Stocchi, J Strauss, R Strub, B Stugu, M Szczekowski, M Szeptycka, T Tabarelli, JP Tavernet, O Tchikilev, A Tilquin, J Timmermans, LG Tkatchev, T Todorov, DZ Toet, A Tomaradze, B Tome, L Tortora, G Transtromer, D Treille, W Trischuk, G Tristram, A Trombini, C Troncon, A Tsirou, M-L Turluer, IA Tyapkin, M Tyndel, S Tzamarias, B Ueberschaer, O Ullaland, V Uvarov, G Valenti, E Vallazza, C Vander Velde, GW Van Apeldoom, P Van Dam, WK Van Doninck, J Van Eldik, N Vassilopoulos, G Vegni, L Ventura, W Venus, F Verbeure, M Verlato, LS Vertogradov, D Vilanova, P Vincent, L Vitale, E Vlasov, AS Vodopyanov, V Vrba, H Wahlen, C Walck, M Weierstall, P Weilhammer, C Weiser, AM Wetherell, D Wicke, JH Wickens, M Wielers, GR Wilkinson, WSC Williams, M Winter, M Witek, K Woschnagg, K Yip, O Yushchenko, F Zach, C Zacharatou, A Zaitsev, A Zalewska, P Zalewski, D Zavrtanik, E Zevgolatakos, NI Zimin, M Zito, D Zontar, R Zuberi, GC Zucchelli, G Zumerle

Measurement of αsfrom jet rates in deep inelastic scattering at HERA

Physics Letters B 363:3 (1995) 201-216

Authors:

M Derrick, D Krakauer, S Magill, D Mikunas, B Musgrave, J Repond, R Stanek, RL Talaga, H Zhang, R Ayad, G Bari, M Basile, L Bellagamba, D Boscherini, A Bruni, G Bruni, P Bruni, G Cara Romeo, G Castellini, M Chiarini, L Cifarelli, F Cindolo, A Contin, M Corradi, I Gialas, P Giusti, G Iacobucci, G Laurenti, G Levi, A Margotti, T Massam, R Nania, C Nemoz, F Palmonari, A Polini, G Sartorelli, R Timellini, Y Zamora Garcia, A Zichichi, A Bargende, A Bornheim, J Crittenden, K Desch, B Diekmann, T Doeker, M Eckert, L Feld, A Frey, M Geerts, M Grothe, H Hartmann, K Heinloth, E Hilger, HP Jakob, UF Katz, S Mengel, J Mollen, E Paul, M Pfeiffer, C Rembser, D Schramm, J Stamm, R Wedemeyer, S Campbell-Robson, A Cassidy, WN Cottingham, N Dyce, B Foster, S George, ME Hayes, GP Heath, HF Heath, CJS Morgado, JA O'Mara, D Piccioni, DG Roff, RJ Tapper, R Yoshida, RR Rau, M Arneodo, M Capua, A Garfagnini, L Iannotti, M Schioppa, G Susinno, A Bernstein, A Caldwell, N Cartiglia, JA Parsons, S Ritz, F Sciulli, PB Straub, L Wai, S Yang, Q Zhu, P Borzemski, J Chwastowski, A Eskreys, K Piotrzkowski, M Zachara

Abstract:

Jet production in deep inelastic scattering for 120 < Q2< 3600 GeV2has been studied using data from an integrated luminosity of 3.2 pb-1collected with the ZEUS detector at HERA. Jets are identified with the JADE algorithm. A cut on the angular distribution of parton emission in the γ*-parton centre-of-mass system minimises the experimental and theoretical uncertainties in the determination of the jet rates. The jet rates, when compared to O(αs2) perturbative QCD calculations, allow a precise determination of αs(Q) in three Q2-intervals. The values are consistent with a running of ifαs(Q), as expected from QCD. Extrapolating to Q = MZ0αs(MZ0) = 0.117 ± 0.005 (stat)-0.005+0.004(systexp) ± 0.007 (systtheory). © 1995.

Measurement of Δ++(1232) production in hadronic Z decays

Physics Letters B 361:1-4 (1995) 207-220

Authors:

P Abreu, W Adam, T Adye, E Agasi, I Ajinenko, R Aleksan, GD Alekseev, PP Allport, S Almehed, SJ Alvsvaag, U Amaldi, S Amato, A Andreazza, ML Andrieux, P Antilogus, V Anykeyev, WD Apel, Y Arnoud, B Åsman, JE Augustin, A Augustinus, P Baillon, P Bambade, F Barao, R Barate, DY Bardin, GJ Barker, A Baroncelli, O Barring, JA Barrio, W Bartl, MJ Bates, M Battaglia, M Baubillier, J Baudot, KH Becks, M Begalli, P Beilliere, Y Belokopytov, AC Benvenuti, M Berggren, D Bertrand, F Bianchi, M Bigi, MS Bilenky, P Billoir, D Bloch, M Blume, S Blyth, V Bocci, T Bolognese, M Bonesini, W Bonivento, PSL Booth, G Borisov, C Bosio, S Bosworth, O Botner, B Bouquet, C Bourdarios, TJV Bowcock, M Bozzo, P Branchini, KD Brand, T Brenke, RA Brenner, C Bricman, L Brillault, RCA Brown, P Bruckman, JM Brunet, L Bugge, T Buran, T Burgsmueller, P Buschmann, A Buys, M Caccia, M Calvi, AJ Camacho Rozas, T Camporesi, V Canale, M Canepa, K Cankocak, F Cao, F Carena, P Carrilho, L Carroll, C Caso, MV Castillo Gimenez, A Cattai, FR Cavallo, L Cerrito, V Chabaud, P Charpentier, L Chaussard, J Chauveau, P Checchia, GA Chelkov, R Chierici, P Chliapnikov

Abstract:

A measurement of the Δ++(1232) inclusive production in hadronic decays of the Z at LEP is presented, based on 1.3 million hadronic events collected by the DELPHI detector in the 1994 LEP running period. The DELPHI ring imaging Cherenkov counters are used for identifying hadrons. The average Δ++(1232) multiplicity per hadronic event is 0.079 ± 0.015 which is more than a factor of two below the JETSET, HERWIG and UCLA model predictions. It agrees with a recently proposed universal mass dependence of particle production rates in e+e- annihilations. © 1995.

Upper limits on the branching ratios τ → μγ and τ → eγ

Physics Letters B 359:3-4 (1995) 411-421

Authors:

P Abreu, W Adam, T Adye, E Agasi, I Ajinenko, R Aleksan, GD Alekseev, PP Allport, S Almehed, SJ Alvsvaag, U Amaldi, S Amato, A Andreazza, ML Andrieux, P Antilogus, WD Apel, Y Arnoud, B Åsman, JE Augustin, A Augustinus, P Baillon, P Bambade, F Barao, R Barate, G Barbiellini, DY Bardin, GJ Barker, A Baroncelli, O Barring, JA Barrio, W Bartl, MJ Bates, M Battaglia, M Baubillier, J Baudot, KH Becks, M Begalli, P Beilliere, Y Belokopytov, AC Benvenuti, M Berggren, D Bertrand, F Bianchi, M Bigi, MS Bilenky, P Billoir, D Bloch, M Blume, S Blyth, V Bocci, T Bolognese, M Bonesini, W Bonivento, W Bonivento, PSL Booth, G Borisov, C Bosio, S Bosworth, O Botner, E Boudinov, B Bouquet, C Bourdarios, TJV Bowcock, M Bozzo, P Branchini, KD Brand, T Brenke, RA Brenner, C Bricman, L Brillault, RCA Brown, P Bruckman, JM Brunet, L Bugge, T Buran, T Burgsmueller, P Buschmann, A Buys, M Caccia, M Calvi, AJ Camacho Rozas, T Camporesi, V Canale, M Canepa, K Cankocak, F Cao, F Carena, P Carrilho, L Carroll, C Caso, MV Castillo Gimenez, A Cattai, FR Cavallo, L Cerrito, V Chabaud, M Chapkin, P Charpentier, L Chaussard, J Chauveau, P Checchia

Abstract:

The DELPHI collaboration has searched for lepton flavour violating decays τ → μγ and τ → μgg using a data sample of about 70 pb-1 of integrated luminosity corresponding to 81 000 produced τ+τ- events. No candidates were found for either of the two modes. This yields branching ratio upper limits of B(τ → eγ) < 1.1 × 10-4 and B(τ → μγ) < 6.2 × 10-5 at 90% confidence level. © 1995.

A measurement of the τ leptonic branching fractions

Physics Letters B 357:4 (1995) 715-724

Authors:

P Abreu, W Adam, T Adye, E Agasi, I Ajinenko, R Aleksan, GD Alekseev, PP Allport, S Almehed, SJ Alvsvaag, U Amaldi, S Amato, A Andreazza, ML Andrieux, P Antilogus, WD Apel, Y Arnoud, B Åsman, JE Augustin, A Augustinus, P Baillon, P Bambade, F Barao, R Barate, DY Bardin, GJ Barker, A Baroncelli, O Barring, JA Barrio, W Bartl, MJ Bates, M Battaglia, M Baubillier, J Baudot, KH Becks, M Begalli, P Beilliere, Y Belokopytov, AC Benvenuti, M Berggren, D Bertrand, F Bianchi, M Bigi, MS Bilenky, P Billoir, D Bloch, M Blume, S Blyth, V Bocci, T Bolognese, M Bonesini, W Bonivento, PSL Booth, G Borisov, C Bosio, S Bosworth, O Botner, E Boudinov, B Bouquet, C Bourdarios, TJV Bowcock, M Bozzo, P Branchini, KD Brand, T Brenke, RA Brenner, C Bricman, L Brillault, RCA Brown, P Bruckman, JM Brunet, L Bugge, T Buran, T Burgsmueller, P Buschmann, A Buys, M Caccia, M Calvi, AJ Camacho Rozas, T Camporesi, V Canale, M Canepa, K Cankocak, F Cao, F Carena, P Carrilho, L Carroll, C Caso, MV Castillo Gimenez, A Cattai, FR Cavallo, L Cerrito, V Chabaud, M Chapkin, P Charpentier, L Chaussard, J Chauveau, P Checchia, GA Chelkov, R Chierici

Abstract:

A sample of 25000 Z0 → τ+τ- events collected by the DELPHI experiment at LEP in 1991 and 1992 is used to measure the leptonic branching fractions of the τ lepton. The results are B(τ → eνν) = (17.51 ± 0.39)% and B(τ → μνν) = (17.02 ± 0.31) %. The ratio of the muon and electron couplings to the weak charged current is measured to be gμ ge = 1.000 ± 0.013, satisfying e-μ universality. The leptonic branching fraction corrected to the value for a massless lepton, assuming e-μ universality, is found to be B(τ → lνν) = (17.50 ± 0.25)%. © 1995.